<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>

	<script>
		
		
		
		
	try{
		var num=Math.ceil(Math.random()*10)
		
		if(num<5){
			console.log(num)
		}else{
			throw new Error('数值太大！')
		}
	}catch(err){
		
		console.log(err)
	}	
		
	console.log(111)
	
	
	//Symbol
	var p1=Symbol('foo')
	var p2=Symbol('foo')
	//== ===
	console.log(p1==p2)
	
	var p3=Symbol('这是一个描述性别的属性')
	var p4=Symbol('这是一个描述年龄的属性')
	
	var people={
		name:'kelly'
	}
	
	people[p3]="女"
	people[p4]=20;
	
	console.log(people)
	console.log(p3.description); //获取他的描述值
	
	console.log(people[p3])
	console.log(people[p4])
	
	
	
	
	
	
	</script>
	</body>
</html>
